American Thoracic Society Journal News Tips for June 2005

June 15, 2005

In an area of high tuberculosis (TB) incidence, investigators found that the age-adjusted rate of disease reinfection after successful treatment for TB was four times that for new cases, according to a study in the American Thoracic Society\’s (ATS) peer-reviewed journal. The objective of the researchers\’ study was to determine the incidence rate of TB attributable to reinfection among those successfully treated for the disease at an epidemiologic fieldsite in Cape Town, South Africa. The median follow-up period was slightly over five years.

In the study, all patients with reported TB in the area between years 1993 to 1998 were followed-up to 2001 for disease either needing retreatment or having recurred. Patients were excluded who were either multi-drug-resistant or who had treatment failure, were transferred, or died during treatment. The researchers restricted analysis to patients for whom DNA fingerprinting of their TB isolates had been obtained.

The incidence of new bacteriologically confirmed TB in the Cape Town area was 313 cases per 100,000 population. In the United States, the rate was 5.1 cases per 100,000 in 2003.

Recurrent TB occurred in 108 (18 percent) of 612 patients for whom the researchers had DNA fingerprints of TB isolates. Of this group, 61 (14 percent) of 447 experienced recurrence after successful treatment, and 47 (28 percent) of the remaining 165 had recurrent disease after they had defaulted on their treatment.

According to the authors, the rate of disease reinfection was approximately seven times the crude incidence rate and approximately four times the age-adjusted incidence rate of new TB in the area.

The study appears in the second issue for June 2005 of the ATS\’s peer-reviewed American Journal of Respiratory and Critical Care Medicine.

DETECTING EARLY LUNG CANCER

Researchers have shown that low-dose spiral computer-based tomographic (CT) screening for the early detection of lung cancer can lead to an early diagnosis in a high proportion of cases, potentially increasing the chances for a cure.

Spanish investigators pointed out that after the initial screening with CT, a possible second step included positron emission tomography (PET) for nodules detected by computerized tomography that were 10 mm or larger, along with smaller growing nodules over 7 mm in size.

Both detection steps were designed to help minimize unnecessary invasive procedures for benign lesions.

According to the authors, lung cancer is one of the leading causes of death in the world. In many countries, it is the most common cancer and the most lethal because the majority of patients are diagnosed in late stages of disease. Less than 20 percent of individuals who suffer from this illness are diagnosed in stages in which curative surgery is an option. The survival rates for early stage disease are quite high, approaching 80 percent in some series. However, the overall survival rates at 5 years are approximately 15 percent.

At the start of the study, all patients who participated were characterized as high risk for lung cancer. Their mean age was 54.7 years, and their median tobacco consumption was 30 pack years.

In the study, lung cancer was detected in 14 patients out of 911 individuals in the protocol. There were 13 non-small cell lung cancers and one small cell lung cancer. Eleven of the 13 non-small cell lung cancers and the one small cell lung case were detected on the initial CT screening.

.All patients with non-small cell lung cancer underwent surgery because they had been diagnosed with stage 1 disease. There were no preoperative surgical biopsies performed. Fine needle aspiration was performed on four PET-positive nodules and two growing PET negative nodules.

The study is published in the second issue for June 2005 of the ATS peer-reviewed American Journal of Respiratory and Critical Care Medicine.

ATS STATEMENT ON HOME CARE FOR RESPIRATORY DISORDERS

In the just published “American Thoracic Society Statement on Home Care for Patients with Respiratory Disorders,” an ad hoc expert subcommittee pointed out that either reducing the frequency of or the length of hospitalization is the key to lowering the total cost of chronic obstructive pulmonary disease (COPD) which affects 11.2 million U.S. adults and cost the nation $37.2 billion during 2004.

Published in the second issue for June 2005 of the ATS peer-reviewed American Journal of Respiratory and Critical Care Medicine, the new statement points out that home care services can offer great potential for patients with respiratory disorders, especially pediatric and geriatric patients, by providing services and equipment at the place of residence for individuals and families who have needs resulting from acute illness, long-term health conditions, permanent disability, or terminal illness.

In the United States, home care includes home health care that offers episodic, post-acute illness assistance on an intermittent basis; hospice care that is palliative, end-of-life care for the terminally ill; chronic home care assistance directed at private duty aid offered on an hourly basis; and, in the home, the provision of and assistance with medical equipment such as oxygen supplies, respiratory equipment, nebulized medications, infusion therapy, and other in-home medical supplies.

According to the report, the most common diagnosis of patients with respiratory disorders referred for home health care is COPD. Slightly over 11 percent of the 7.6 million patients who received home health care in 1998 had respiratory system disease as their primary diagnosis. COPD and pneumonia are, respectively, the fourth and fifth most frequent reasons for hospital discharge to home care for Medicare patients.

The expert subcommittee pointed out that chest physicians and pulmonologists need to recognize that earlier hospital discharge, or avoidance of hospital care altogether, are important premises upon which home health care referrals can be made.